var arr = [
    {
        id:1,
        name:"moyu",
        age:23,
    },
    {
        id:2,
        name:"tim",
        age:18,
    },
    {
        id:3,
        name:"terry",
        age:12,
    },
];
Array.prototype.myForEach = function(handler){
    for(var i=0;i<this.length;i++){
        var item = this[i];
        handler(item,i)
    }
}
arr.myForEach(function(item,index){
    console.log(item)
})
